Totally Objects - Boolean Logic (Version 5.5 [1.0])


This Totally Objects product for IBM VisualAge Smalltalk Boolean logic to be applied to attributes of parts using the Composition Editor. How often have you required a button to be enabled only if the selection is valid in two lists? Or have often have you wanted a visual part to be enable if the selection is NOT valid in a list? The usual way to solve these problems is to use Event-to-Script or Attribute-from-Script connections. This product removes the need for these scripts by representing the Boolean logic as a number of connected parts.


This Totally Objects product has been packaged as configuration maps. To import them into your library select 'Browse Configuration Maps' from the 'Tools' menu of the 'System Transcript'. In the 'Configuration Maps Browser' select 'Import...' from the 'Names' menu and select the file tobbl5-5_1-0-*.dat. You should then select the configuration maps contained within this file.

Note that future releases of the product may be made without changes to this manual (for bug fixes etc). Because of this, the file name shown above may be different to the that delivered with this manual.

To load the configuration maps into your image select the latest version of each in the 'Configuration Maps Browser' and select 'Load With Required Maps' from the 'Editions' menu.

The directory 'tobbool' and its contents should be copied to the root directory of your VAST intallation.


Each of the Boolean operators NOT, AND, OR, XOR, NAND, NOR, XNOR are available as parts from the 'Totally Objects - Boolean Logic' category in the palette of the Composition Editor. Each of these, except NOT, has three attributes 'in1', 'in2' and 'out'. Boolean attributes of other parts can be connected to 'in1' and 'in2', 'out' can then be connected to Boolean attributes of any parts requiring the result of the operation.

For example, suppose we have a window with two lists (named 'List1' and 'List2') and a button. We want the button to be enabled only when both lists have a valid selection. First drop and AND part into a free space in the Composition Editor. Connect the 'selectionIsValid' attribute of 'List1' to the 'in1' attribute of the AND part. Similarly, connect the 'selectionIsValid' attribute of 'List2' to the 'in2' attribute of the AND part. The 'out' attribute of the AND part should then be connected to the 'enabled' attribute of the button.

If required, multiple Boolean logic parts can be chained together by connecting the 'out' attribute of one part to the 'in1' or 'in2' of another part. Make sure, however, that you only ever have at most one connection to any input. If the attributes 'in1' and 'in2' are left unconnected then their value is false; this can be changed by using the Properties window.

As you might expect, the NOT part has only one input, 'in'.


Any applications using this product should have TobBooleanLogicPartsRunApp as a prerequisite. The other applications and icons included in this product are not needed at runtime.

Further Information